diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 56689ef1a15..88b08acf2ff 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1379,6 +1379,10 @@ and is between 256 and 4096 characters. It is defined in the file
 
 	nox2apic	[X86-64,APIC] Do not enable x2APIC mode.
 
+	x2apic_phys	[X86-64,APIC] Use x2apic physical mode instead of
+			default x2apic cluster mode on platforms
+			supporting x2apic.
+
 	noltlbs		[PPC] Do not use large page/tlb entries for kernel
 			lowmem mapping on PPC40x.